Recirculating sewerage system

ABSTRACT

A recirculating sewerage system comprising at least one water closet, a recirculating tank including effluent receiving and pumping chambers separated by a common wall, a pump including a filtering element for drawing liquid from the pumping chamber and for directing the drawn liquid to the water closet to flush same, and a drainage opening defined in the bottom of the recirculating tank. The common wall including a filter for restricting the flow of bulk waste including paper products from the effluent receiving chamber to the pumping chamber; an opening; a drainage valve selectively sized for placement within the common wall opening and selectively displaceable from a first position whereat the drainage opening is closed to a second position whereat the drainage valve is open. Sealing means for effectively preventing the passage of effluent from the effluent receiving chamber through the common wall opening into the pumping chamber when the drainage valve is at the first position. The displacement of the drainage valve to the second position establishing a direct passage from each of the chambers to the drainage opening whereby both chambers will be completely drained.

United States Patent n91 Cornish et al.

[ Aug. '13, 1974 RECIRCULATING SEWERAGE SYSTEM [75] Inventors: Alan H. Cornish, Newington, Conn.;

George W. Foster, Los Angeles; Alexander J. Campbell, Altadena, both of Calif.

[73] Assignee: Koehler-Dayton, lnc., New Britain,

Conn.

[22] Filed: Jan. 24, 1973 [21] Appl. No.: 326,435

[52] US. Cl 4/10, 4/89, 210/152, 210/167, 210/196 [51] Int. Cl. E03d 5/01, E03d 5/16 [58] Field of Search 4/8, 10, 78, 90, 115, 89; 210/74, 152, 167, 195, 196, 248, 434

[56] References Cited UNITED STATES PATENTS 3,306,448 2/1967 Baker 210/434 X 3,501,778 3/1970 Minniear et al. 4/10 3,579,646 5/1971 Lekberg 4/10 3,579,651 5/1971 Russo 4/10 X 3,628,196 12/1971 Quiram et al 4/115 3,633,218 l/l972 Lekberg 4/10 3,751,735 8/1973 Sargent et al 4/10 Primary Examiner-Samih N. Zaharna Assistant Examiner-Robert l-l. Spitzer Attorney, Agent, or Firm-Spencer T. Smith [57] ABSTRACT A recirculating sewerage system comprising at least one water closet, a recirculating tank including effluent receiving and pumping chambers separated by a common wall, a pump including a filtering element for drawing liquid from the pumping chamber and for directing the drawn liquid to the water closet to flush same, and a drainage opening defined in the bottom of the recirculating tank. The common wall including a filterfor restricting the flow of bulk waste including paper products from the effluent receiving chamber to the pumping chamber; an opening; a drainage valve selectively sized for placement within the common wall opening and selectively displaceable from a first position whereat the drainage opening is closed to a second position whereat the drainage valve is open. Sealing means for effectively preventing the passage of effluent from the effluent receiving chamber through the common wall opening into the pumping chamber when the drainage valve is at the first position. The displacement of the drainage valve to the second position establishing a direct passage from each of the chambers to the drainage opening whereby both chambers will be completely drained.

3 Claims, 3 Drawing Figures PATENTED 315374 3.828.372

Fig-l 1 RECIRCULATING SEWERAGE SYSTEM This invention relates to recirculating sewerage systems for use on vehicles such as buses, trains and planes, and for use in other structures where an unlimited source of pure water is either not available or cannot be stored in the limited environment in which the system is located.

Recirculating sewerage systems receive effluent from a water closet or the like and periodically recirculate a portion of the liquid component thereof to flush the water closet. When flush pumps are utilized which include intake filters for effecting the necessary filtration, care must be exercised to prevent bulk waste including solid sewerage and paper products such as toilet tissue and paper towels from being rapidly drawn into choking engagement with the pump inlet whereby the operation of the pump will be brought to a halt. Conventionally, recirculating tanks have included an effluent receiving chamber and a downstream pumping chamber. The pumping chamber communicates with the effluent receiving chamber through a secondary latticework filter which restricts the flow of the bulk waste from the effluent receiving chamber to the pumping chamber. The flush pump is located within the pumping chamber and a reservoir of liquid substantially free of bulk waste is thereby provided for the pump to assure the continued satisfactory operation of the sewerage system.

It has been found that portions of the bulk waste such as toilet tissue, hand towels and the like pass through this secondary filter and are not backwashed through the secondary filter when the recirculating tank is drained through an outlet opening in the effluent receiving chamber.

Accordingly, it is an object of the present invention to provide a recirculating sewerage system wherein a separate pumping chamber will be provided for the recirculating pumps but wherein when the recirculating tank is drained bulk waste which finds its way into the pumping chamber will be automatically and completely removed therefrom.

Among the advantages of the present invention is the provision of a recirculating sewerage system wherein the efficiency of the recirculating pumps is not progressively decreased as a result of paper products accumulating within the pumping chamber.

Other objects and advantges of the present invention will become apparent from the following portion of the specification and from the accompanying drawings, which illustrate in accordance with the mandate of the patent statutes a presently preferred embodiment incorporating the principals of the invention.

Referring to the drawings:

FIG. 1 is a schematic representation of the components of the recirculating sewerage system made in accordance with the teachings of the present invention;

FIG. 2 is a top view, partly in section, illustrating the recirculating tank of the recirculating sewerage system schematically illustrated in FIG. 1; and

FlG. 3 is an elevational view, partly in section, of a portion of the recirculating tank illustrated in FIG. 2.

A recirculating sewerage system made in accordance with the teachings of the present invention is illustrated in FIG. 1 The system includes a water closet or a plurality of water closets 10, a recirculating tank 12 for receiving effluent through inlet ports 13 (FIG. 2) from the water closet, and a plurality of flush pumps 14 for recirculating flushing medium filtered by a filter 16 to the water closet.

The recirculating tank 12 is initially primed with a charge of clean water which may either be introduced into the recirculating tank directly through a suitable access port (not shown) or indirectly by placing the charge in the water closet 14 and allowing the charge to flow into the recirculating tank. Color and odor control additives may be added to this initial charge.

The flush pumps 14 include inlet filters and have a construction similar to that of the flush pumps disclosed in U.S. Pat. No. 3,067,433 and reference may be had to that patent for the specific details of these flush pumps. The flush pumps are located within a secondary or pumping chamber 20 (FIG. 2) of the recirculating tank, which is situated downstream from a principal or effluent receiving chamber 22 of the recirculating tank and which is separated therefrom by a secondary filter element 24. The secondary filter 24 is of a latticework construction including a plurality of horizontally and vertically spaced, vertically elongated, rectangular punched-out openings. During operation of such a system, tissue paper and paper towels migrate through the latticework into the pumping chamber.

Conventionally, the recirculating tank is drained through a discharge opening located within the effluent receiving chamber but it has been found that the backwashing of the liquid effluent from the pumping chamber through the secondary filter to the effluent receiving chamber is not sufficiently strong to remove the paper products which become located within the pumping chamber. Accordingly, paper products progressively accumulate within the pumping chamber and increasingly interfere with the operation of the flush pumps.

To prevent such accumulation, wall 26 which separates the effluent receiving 22 and pumping 20 chambers of the recirculating tank 12 of the recirculating sewerage system made in accordance with the teachings of the present invention not only includes the secondary filter 24 but additionally includes a drainage valve 28 having a construction similar to that of the drainage valve disclosed in U.S. Pat. No. 3,501,778. The drainage valve (FIG. 3) includes a downwardly extending metallic tube 30 which is secured to the top of the recirculating tank and a metallic lower tube 32 adapted to fit snugly inside the upper tube and to be telescopically displaceable relative thereto upon actuation of a drainage valve control (not shown) from a first closed position wherein a valve 34 mounted on the bottom of the lower tube is seated on the valve seat 36 formed in the bottom of the tank in communication with the discharge opening to a second open position wherein the valve is displaced out of engagement with the valve seat. Reference may be had to the above patent for further details of the drainage valve.

A pair of opposing metallic struts 40 are secured to the upper tube 30 and extend substantially from the top to the bottom of the recirculating tank and rubber strips 42 are secured to these struts and are selectively configured so that when the drainage valve is in the closed position sealing engagement will be established between these strips and the top and bottom walls of the tank, the adjacent walls of the common wall 26 and opposing sides of the lower tube.

It can therefore be appreciated that when the drainage valve 28 is closed, the only passageway through the common wall 26 is through the secondary filter 24; but when the drainage valve is in the open position, both the effluent receiving and pumping chambers commu-,

nicate with the drainage opening whereby both chambers will be simultaneously and completely drained.

After the recirculating tank is periodically drained, the effluent receiving chamber may be rinsed with a clean flushing medium from a suitable pressurized source 46 (FIG. 1).

Having thus disclosed our invention, what is claimed l. A recirculating sewerage system comprising a recirculating tank including effluent receiving and pumping chambers separated by a common wall, at least one water closet, means for discharging the effluent flushed from said closet into said receiving chamber, means including a pump for drawing liquid from said pumping chamber and for directing the drawn liquid to said water closet to flush same, and a drainage opening defined in the bottom of said recirculating tank, said common wall including filter means for permitting the flow of liquid but restricting the flow of bulk waste including paper products from said effluent receiving chamber to said pumping chamber, an opening, a drain valve assembly selectively sized so that when placed within said common wall opening, the common wall opening will be closed to the passage of bulk waste from said receiving chamber through said opening into said pumping chamber and selectively displaceable from a first position whereat said drainage opening and said common wall opening are closed to a second position whereat said drainage opening and said common wall opening are open,

whereby displacement of said drain valve assembly to said second position will establish a direct passage from each of said chambers to said drainage opening whereby both chambers can be completely drained.

2. A recirculating sewerage system according to claim 1 wherein said drain valve assembly comprises an upper tube secured to said recirculating tank,

a lower tube slidably, telescopically displaceable therewith, and

valve means secured to the lower end of said lower tube.

3. A recirculating sewerage system according to claim 2 further comprising sealing means for effectively preventing the passage of effluent from said effluent receiving chamber to said pumping chamber through said common wall opening when said drain valve assembly is at said first position including a pair of struts secured to said upper tube and extending substantially from the top of said upper tube to the bottom of said lower tube when said drain valve assembly is at said first position,

rubber sealing strips secured to each of said struts, said strips being selectively configured for sealingly engaging the adjacent common wall portions and said lower tube when said drain valve assembly is at said first position. 

1. A recirculating sewerage system comprising a recirculating tank including effluent receiving and pumping chambers separated by a common wall, at least one water closet, means for discharging the effluent flushed from said closet into said receiving chamber, means including a pump for drawing liquid from said pumping chamber and for directing the drawn liquid to said water closet to flush same, and a drainage opening defined in the bottom of said recirculating tank, said common wall including filter means for permitting the flow of liquid but restricting the flow of bulk waste including paper products from said effluent receiving chamber to said pumping chamber, an opening, a drain valve assembly selectively sized so that when placed within said common wall opening, the common wall opening will be closed to the passage of bulk waste from said receiving chamber through said opening into said pumping chamber and selectively displaceable from a first position whereat said drainage opening and said common wall opening are closed to a second position whereat said drainage opening and said common wall opening are open, whereby displacement of said drain valve assembly to said second position will establish a direct passage from each of said chambers to said drainage opening whereby both chambers can be completely drained.
 2. A recirculating sewerage system according to claim 1 wherein said drain valve assembly comprises an upper tube secured to said recirculating tank, a lower tube slidably, telescopically displaceable therewith, and valve means secured to the lower end of said lower tube.
 3. A recirculating sewerage system according to claim 2 further comprising sealing means for effectively preventing the passage of effluent from said effluent receiving chamber to said pumping chamber through said common wall opening when said drain valve assembly is at said first position including a pair of struts secured to said upper tube and extending substantially from the top of said upper tube to the bottom of said lower tube when said drain valve assembly is at said first position, rubber sealing strips secured to each of said struts, said strips being selectively configured for sealingly engaging the adjacent common wall portions and said lower tube when said drain valve assembly is at said first position. 